Exhaust chimneys for furnaces, boilers or the like have been generally constructed on-site to accomodate the particular building or location. Later, it has been found that chimneys constructed from prefabricated sections are adaptable to most building or remodeling projects. However, it has been found that while prefabricated chimney sections work well under certain load conditions, these same sections fail under different conditions after use has begun as the imposed load places a large strain on certain sections of the chimney and the sections become misaligned and can allow the escape of exhaust fumes into the building. Also, if opposing flanges from two abutting chimney sections do not properly align the required seal is not formed and fire or exhaust hazards can occur.
With this background in mind the present invention was developed and one of its objectives is to provide a prefabricated multi-wall chimney section which can be easily assembled on-site by unskilled workmen using ordinary tools.
It is another objective of the present invention to provide a fastening means for sealing multiple wall chimney sections which are efficient and easy to handle and position in place.
It is still another objective of the present invention to provide a prefabricated multi-wall chimney section having an inner tube of stainless steel with an end flange also of stainless steel.
It is another objective of the invention to provide a chimney joint which is easy to assemble using ordinary tools and which meets all building and safety codes.
It is still another objective of the present invention to provide a multi-wall chimney section having an end flange with a rectangularly-shaped cross-section.
Other objectives and advantages of the present invention will be demonstrated in more detail below.